Enzyme causes chronic pain

An enzyme responsible for making pain last after nerve injury has been discovered in mice. The finding could lead to new treatments for chronic pain in humans.

Raised levels of the enzyme, called protein kinase M zeta, were found in the brains of injured mice. The researchers then knocked out the gene responsible for producing the enzyme. These GM mice experience less or no chronic pain after nerve injury.

Many painkillers are ineffective for treating chronic pain. The research may allow new medicines to be designed that block this enzyme.